Compass Math Sample
Converting Fractions , Decimals, and Percents
Changing Decimals to Percents (%): • Move the decimal two places to the right and add the percent sign Ex.: .25 = 25% Changing a Percent to a Decimal: • Move the decimal two places to the left and remove the percent sign (%) Ex.: 25% = .25 Change a Fraction to a Decimal : • Divide the numerator (top number) by the denominator (bottom number)
Change a Fraction to a Percent: Change a Decimal to a Fraction: • Write your decimal without the decimal point as your numerator (top number). Change a Percent to a Fraction: |
1. Fill in the empty boxes.
Decimal | Fraction | Percent (%) |
.25 | ||
5/8 | ||
50% | ||
2/3 | ||
.45 | ||
30% | ||
1/5 | ||
.75 |
PERCENTS
Percent problems are made up of four elements: 1. The WHOLE is the number value after the word Of 2. The PART is listed before or just after the word IS 3. The PERCENT always has a percent sign (%) 4. All percents are based on 100 5. The PERCENT of the WHOLE is the PART Solving for PART : 1. Identify the parts 2. Place the known information on a grid 3. Multiply the diagonals 4. Divide the answer by the number that is left Ex.: What is 30% of 770?
770 x 30 = 23100 |
1. What is .5% of 300?
2. 65% of 240 is what?
3. 32% of the vote has been counted. If 775 people voted, how many votes have
been
counted so far?
4. Kim bought a desk for $55.00. After she refinished it, she sold it at 250% of
its
original price. What did she sell it for?
5. 38% of the families in the neighborhood are against having a gas station
nearby. If
200 families are in the area, how many are against having a gas station?
Solving for PERCENT: 1. Identify the parts 2. Place the known information on a grid 3. Multiply the diagonals 4. Divide the answer by the number that is left 5. Add the percent sign Ex.: 13 is what % of 25
13 x 100 = 1300 |
1. 62 is what percent of 124?
2. 83 is what % of 332?
3. Out of the 51 questions on the test, Tom answered 34 correctly. What percent
of the total is
that?
4. Sue pays $14.40 a month in union dues. She earns $1800 a month. What percent
of this
monthly pay goes to union dues?
5. The Johnson's paid $2320 in property tax on their $160,000 home. What % is
their tax rate?
Solving for the Whole: 1. Identify the parts 2. Place the known information on a grid 3. Multiply the diagonals 4. Divide the answer by the number that is left Ex.: 50% of what is 290.
290 x 100 = 29000 |
1. 175% of what is 770?
2. 844 is 80% of what?
3. Max paid $42 tax on the furniture he bought. If the sales tax was 7%, what
was the
cost of the furniture?
4. To buy a house, the Smiths need a down payment of 20%. They have saved
$25,000. What is the most the Smiths can pay for a house?
5. Joyce received a $6.75 tip. It was 15% of the cost of the meal. What was the
cost of
the meal?
Ratios
• Relating part of an amount to the whole or
another part Ex.: You have a basket of 20 balls: 9 white and 11 red What is the ratio of white balls to the red balls? 9 (white balls) 11 (red balls)? |
• A statement comparing two ratios Ex.: 1 is to 2 as 8 is to 16
Solving for the Unknown in Proportions : • N is the missing number |
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